Forget demi-celebs like Ashton Kutcher (who?), National Treasures like Stephen Fry or even bona fide media moguls like Oprah Winfrey - these days the real pioneers of Twitter are doing it from 350 miles above the Earth's surface.

In case you can't read the picture, the message reads: "From orbit: Launch was awesome!! I am feeling great, working hard, & enjoying the magificent views, the adventure of a lifetime has begun!"

Massimino, who was on board the Atlantis when it launched from Cape Canaveral earlier this week, is the first in a string of astronauts who are going to be using social media tools like Twitter and YouTube from aboard the shuttle and international space station in the coming months.

Except... well, it's not quite what it seems.

Etan Horowitz of the Orlando Sentinel explains that there's no live connection: instead, Astro Mike must compose his message on a computer and then beam the message in an email down to ground control. Some lucky Nasa goon then gets to pick up his message and paste it into Twitter, where it becomes visible for all of us on the internet.

Of course, Twitter has been used to document the ups and downs of space travel before: most notably in the form of the Mars Phoenix account, which saw a stream of in-character messages from the interplanetary rover... until it all went wrong in the frigid Martian winter.

But Massimino's Twitter-by-proxy situation isn't just because there's no internet aboard the shuttle, though: Nasa's very careful about the messages about it that reach the public. I asked Ariel Waldman, the founder of Spacehack.org what was going on: she said that something like this would most likely require many levels of approval from inside Nasa itself, and that messages are probably carefully monitored for any unwanted content.

No chance, then, that we'll ever see astronauts telling us the ugly truth about life among the stars: "Bloody boring up here: space toilet's broken and now the computer's playing up. It keeps saying 'I'm sorry, Dave, I can't do that'. WTF?!"